The present invention relates to a fuel cell system and, more particularly, an auto-thermal reformer fuel cell system to produce electricity.
Fuel cell power plants for producing electricity are well known in the art. U.S. Pat. No. 3,976,507 discloses a pressurized fuel cell power plant which operates at a pressure greater than ambient pressure. While the power plant disclosed in U.S. Pat. No. 3,976,507 is effective and useful for generating electricity, the fact that the plant operates under pressure does not render it particularly useable for an auto-thermal reformer fuel cell system with vehicular applications. In a low pressure auto-thermal reformer fuel cell system, the size of the system and the pressure drop experienced during operation of the system are critical factors in producing an effective, compact system which is useable in vehicular applications.
Naturally, it would be highly desirable to produce an auto-thermal reformer fuel cell system which can operate effectively at ambient pressure while maintaining a compact size which is suitable for use in the system. In order to achieve the foregoing, each component in the auto-thermal reformer fuel cell system must be designed in a manner which takes into consideration the allowable pressure drop which may occur within the system and the sized limitation constraints necessary to make such a system practical. Therefore, any savings in size and pressure drop which can be obtained with any of the system components is highly desirable. Accordingly, it is a principal object of the present invention to provide a compact precooler which is useful in an auto-thermal reformer fuel cell system.
It is a particular object of the present invention to provide a compact precooler which is effective in reducing the temperature of a reformer exit gas stream while ensuring minimal pressure drop.
It is a still further object of the present invention to provide a compact precooler between an auto-thermal reformer and low temperature shift converter which provides sufficient residence time to effectively cool the reformer exit gas stream to a desired temperature and evaporate all water used in the precooler.
It is a still further object of the present invention to provide a process for cooling a reformer exit gas stream in an effective manner while limiting pressure drop.
Further objects and advantages of the present invention will appear hereinbelow.